NonStop Networking Overview

For the purposes of this discussion we make the distinction between:
• Network Scalability
• Application Scalability
Network Scalability
Network scalability refers to the use of multiple physical interfaces to accommodate bandwidth
requirements for which a single network interface is insufficient. You can achieve network scalability
by having multiple network interfaces on multiple hosts or by having a multi-homed host (a single
system that has multiple network interfaces). You can make this form of scalability either explicit
or transparent. If explicit, then both ends of the connection simply accommodate multiple interfaces
by specifying a list of IP addresses.
To make network scalability transparent with a multi-homed host or with multiple hosts, you can
use the Domain Name System (DNS) and have the multiple interfaces share a single, externally
visible name. One way to have multiple interfaces share a name, is to have a DNS name server
process on each of the subnets and configure each of those name server processes to return the
IP address of the host that is also on that subnet (Figure 5).
Figure 5 Transparent Network Scalability, Multiple Hosts
In the example shown in Figure 5, there are four DNS name server processes, one on each subnet.
Each name server process is configured to return the IP address of the host’s interface on that
16 Networking on Integrity NonStop Systems